This prospective study of the people of Graciosa Bay in the Solomon Islands is designed to investigate the dynamics of hepatitis B virus infection in a human populations. The analysis is directed toward clarifying the role of genetic, cultural and environmental factors in the natural history of this infection. A census and prevalence rates of hepatitis B surface antigen and antibody in the total population were determined in 1974. The proposed work involved retesting the entire population to determine incidence rates of acute and chronic hepatitis B infections and identify associated risk factors. BIBLIOGRAPHIC REFERENCES: Mazzur, S. Subtypes of HbsAg in Oceania. Proceedings of the First International Workshop of HbsAg Subtypes. Biblio. Haemat. 42:48-52, 1976. Mazzur, S. Genetic mimicry by hepatitis B virus. Nature 261:316-317, 1976.